menu and adjustments

menu:
- subfolder support, if there is a subfolder with a GUI folder it'll get
added as submenu
adjustments:
- installGUI is adjusted to fit new structure
- all rigging tools adjusted to fit the new structure
MG_pathSpine

- all generated nodes are named
- twistend and skin joints are aligned to twiststart
Merge pull request #33 from tokejepsen/update1.2

Menu, restructure adjustments and MG_pathSpine